Allow only specific user access Add Listing page

I want to only allow a specific user to access a specific CPT Add Listing page, example I have created a CPT named gd_agent

I can give this specific url to my agent user only :
/add-listing/?listing_type=gd_agent

But however, I do not want other users to be able to add this gd_agent, thus is check the Disable frontend add (Prevent this post type from being added from the frontend).
When I do this way, gd_agent add listing in the Listing panel on sidebar is disappear, but the specific URL /add-listing/?listing_type=gd_agent not working.

How can I get a turnaround for this?

I still want my agent users to add gd_agent listing through frontend.